Tokumura A, Yoshida J, Okasaka N, Fukuzawa K, Tsukatani H
Thromb Res. 1987 Apr 1;46(1):153-61. doi: 10.1016/0049-3848(87)90215-5.
Rabbit platelets pretreated with CV-3988 had reduced responsiveness to platelet activating factor(PAF) even after the platelets had been washed with a buffer. This was due to its tight binding to receptor sites for PAF, but not conformational changes of the receptor, because the platelets that were pretreated with CV-3988 and then washed with buffer containing 0.5% bovine serum albumin showed full responsiveness to PAF. In contrast, the reduced responsiveness of PAF-pretreated rabbit platelets was not reversed by washing with buffer containing 0.5% BSA. The PAF-pretreated platelets showed significantly lower responsiveness to 1-O-hexadecyl-2-O-monomethylaminocarbonyl-sn-glycero-3-phosphochol ine (MC-PAF) than to PAF, although MC-PAF had the same potency as PAF on inducing aggregation of normal rabbit platelets by interacting with receptor sites for PAF. These results suggest that the desensitization is accompanied by a decreased affinity of receptor sites for PAF or reduced efficiency in coupling of activated receptor to regulatory protein in plasma membranes rather than loss of receptor sites.
用CV - 3988预处理的兔血小板，即使在用缓冲液洗涤后，对血小板活化因子（PAF）的反应性仍降低。这是由于其与PAF受体位点紧密结合，而非受体的构象变化，因为先用CV - 3988预处理，然后用含0.5%牛血清白蛋白的缓冲液洗涤的血小板对PAF显示出完全反应性。相反，用含0.5%牛血清白蛋白的缓冲液洗涤不能逆转PAF预处理的兔血小板降低的反应性。PAF预处理的血小板对1 - O - 十六烷基 - 2 - O - 单甲基氨基羰基 - sn - 甘油 - 3 - 磷酸胆碱（MC - PAF）的反应性明显低于对PAF的反应性，尽管MC - PAF通过与PAF受体位点相互作用在诱导正常兔血小板聚集方面与PAF具有相同效力。这些结果表明，脱敏伴随着PAF受体位点亲和力降低或活化受体与质膜中调节蛋白偶联效率降低，而非受体位点丧失。
